State television reported 20,000 houses destroyed on one island alone.
The island, Haingyi, is around 200km southwest of Yangon on the western fringes of the Irrawaddy delta.
Nagris, which had been gathering steam in the Bay of Bengal for several days, devastated the country's leafy main city, littering the streets with overturned cars, fallen trees and debris from battered buildings.
"Utter war zone," one diplomat said in Bangkok.
"Trees across all streets. Utility poles down. Hospitals devastated. Clean water scarce."
Newspapers said only one in four buildings were left standing in Laputta and Kyaik Lat, two towns deep in the rice-producing region. There were no details of casualties.
In Yangon, many roofs were ripped off even sturdy buildings, suggesting damage would be severe in the shanty towns that lie on its outskirts.
Foreign aid workers, their movements restricted by the ruling military junta, struggled to reach many impoverished areas to assess the impact.
"I have never seen anything like it," one retired government worker said.
"It reminded me of when Hurricane Katrina hit the US."
The former capital was without power and water yesterday and food prices had doubled overnight, with many shopkeepers unsure of when they would be able to replenish stocks.
Most shops had sold out of candles.
The regime declared a disaster in five states and government TV carried footage of soldiers clearing trees from roads and Premier Thein Sein meeting people sheltering in a Buddhist pagoda.
Hi, everyone.
Mice to meet to you.
My name is Taka.
Please call me Taka.
Today, Shin invited me for this community.
I really interested in this community.
So, I'd like to join tomorrow.
P.S Now, I lent laptop from Korean friend.
So, I can't use Japanese.